Upgrading to 720cc secondaries-any probs I should lookout for?
 

Either today or tomorrow I'll be replacing my secondary injectors with 720cc injectors. I'm going to need to drive about 45 miles to get to a place where I can dyno tune it. Will driving on the upgraded injectors prior to tuning be a problem? I've also got an SAFC and 3rd gen fuel pump.
TIA

I "believe" the 88s were High Impedance and if so, you'll to put the 10 watt, 10 ohm resistors inline for each injector.

http://www.rotaryresurrection.com/injector.html

B

Thanks for the info and instructions. My injectors came with the resistors so I'll be installing them as well. I was wondering if there would be any problems driving it with the new injectors un-tuned.

just check with a multimeter and if everything is ok you should be fine

worst case scenerio is you run pig rich when they open up.

To run with 720cc/min secondary injectors, set all corrections above 3800rpm to -24%. This will make the ECU inject the same amount of fuel at it would with stock injectors, and the engine will run completely normally.

At -24% he'd be running ~550ccs, will this be a problem with his hybrid turbo?

I might be totally wrong here, but if you have an upgraded turbo, you better have 720 primaries and secondaries. How much boost are you running?

-Joe

As far as I can tell from his post, he's just running 720 secondaries, not 720's all around. So, you'd set the correction factor to -13 percent above 3800 rpms.

When there is no need for the extra fuel, why waste it? The safc has a high and low map. On the high map the correction factor would be different depending on how much fuel he needs to inject.

This is a good idea, pre 3800 rpms on stock 550 injectors can be a deadly zone under high load.

Stock primaries, and I'm installing 720 secondaries.
Right now I'm running 12 lbs of boost. Been that way on the stock injectors(all 4 of them) for the past 2 years of so. At peak boost, my A/F meter is always fairly deep into the green(rich).

So why are you upgrading the injectors? Do you have further plans?

FMIC going in this week probably. I'm researching water injection-so I may go that route as well.